Conditional validation with databridge

Conditional validation with databridge

Hello i use to do the conditional validation with cliente side validation but today when i try to do that i noticed that since i have databridge it is no longer in the behaviors, how can i accomplish this with databridge

i have a select menu on an update page for categories when it loads it has selected the category where it belongs from the database, i have a file field also that i can upload a picture this picture is saved with the category selected in the menu field (uploaded to a folder with the category id, if i dont change category i dont need to upload a picture but if i do change it i need to upload the picture in order for it to be uploaded in that category folder, i use to do a complex client side validation for this task but now i have no idea how